Alert archive / Iowa / Tornado Warnings in 1994

Tornado Warning 17, NWS Sioux Falls, SD

July 20, 1994Woodbury County, Iowa

NWS Sioux Falls, SD issued this tornado warning at Jul 20, 1994, 6:18 PM CDT for Woodbury County, Iowa. It was in force for 12 min.

The area

The counties it named.

The facts

Issued
Jul 20, 1994, 6:18 PM CDT (23:18 UTC)
Expired
Jul 20, 1994, 6:30 PM CDT
In force
12 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Woodbury County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.3 hours before the alert went out and 122 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 1994-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 1994-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -143 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1517 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
-143 m²/s²
0-3 km storm-relative helicity
-201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KSUX 202319
TORSUX
IAC193-202330-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SIOUX CITY IA
618 PM CDT WED JUL 20 1994
 
THE NATIONAL WEATHER SERVICE IN SIOUX CITY HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  630 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN WEST CENTRAL IOWA
 
   ...SOUTHWESTERN WOODBURY COUNTY
 
AT 612 PM CDT A TORNADO WAS 15 MILES SOUTHEAST OF SIOUX CITY OR NEAR
SALIX IOWA. MOVEMENT WAS NORTHEAST AT 20 MILES AN HOUR. THE TORNADO WILL
MOVE NEAR SALIX AND SARGEANT BLUFF IOWA BETWEEN 615 AND 630 PM.
 
 
THIS IS A DANGEROUS STORM!!  TAKE COVER IMMEDIATELY.  IF YOU ARE
IN A STRONG BUILDING GO TO AN INTERIOR ROOM ON THE LOWEST FLOOR.
ABANDON CARS AND MOBILE HOMES FOR A REINFORCED BUILDING OR GET
INTO A DITCH OR DEPRESSION...COVER YOUR HEAD WITH YOUR HANDS.
 
HOPPES

Nearby

Tornado Warnings in Iowa, 1994Every tornado warning in 1994Tornadoes in 1994

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.